package com.yuan;

public class circle {
   private double r;

    public circle() {
    }

    public circle(double r) {
        this.r = r;
    }

    public double getR() {
        return r;
    }

    public void setR(double r) {
        this.r = r;
    }
    public void ff(){
        double pai=3.14;
        double mj=(r+r)*pai;
        System.out.println("圆的面积是"+mj);
    }
}
